Initiation time

The time for initiation of carbonation-induced corrosion is the time required for the carbonation front to reach a depth equal to the thickness of the concrete cover. It depends on all the factors mentioned above (that influence the carbonation rate) and on the thickness of the concrete cover. If the evolution of carbonation in the course of time and the thickness of the concrete cover are known, the initiation time can be evaluated. It should, however, be taken into consideration that the carbonation front may not be uniform across the concrete surface. 

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Off-line analysis of stored data review of the stored data, organize data in different presentation windows, plot AE and plant parameters data so as to enable comparison and coirelation with the possibility to present data (histogram of AE events vs position, plant parameters and/or AE parameters vs time) conditioned in terms of time interval (initial time, final time) and/or position interval (defined portion of the component = initial coordinate, final coordinate) and/or plant parameters intervals (one or more plant parameters = initial value, final value). 

The time-dependent Sclirodinger equation allows the precise detemiination of the wavefimctioii at any time t from knowledge of the wavefimctioii at some initial time, provided that the forces acting witiiin the system are known (these are required to construct the Hamiltonian). While this suggests that quaiitum mechanics has a detemihiistic component, it must be emphasized that it is not the observable system properties that evolve in a precisely specified way, but rather the probabilities associated with values that might be found for them in a measurement. 

In an extension of traditional CIDNP methods, Closs and co-workers developed time-resolved CIDNP (TR-CIDNP) m the late 1970s [24, 25 and 26]. The initial time-resolved experiments had a time resolution in the... 

There is another approaeh that ean be used to find energy levels and is espeeially straightforward to use for systems whose Sehrodinger equations are separable. The so-ealled elassieal action (denoted S) of a partiele moving with momentum p along a path leading from initial eoordinate qi at initial time q to a final eoordinate qf at time tf is defined by ... 

F(t)=Zk QcVk exp(-itEk/fe). The relative amplitudes Ck are determined by knowledge of the state at the initial time this depends on how the system has been prepared in an earlier experiment. Just as Newton s laws of motion do not fully determine the time evolution of a elassieal system (i.e., the eoordinates and momenta must be known at some initial time), the Sehrodinger equation must be aeeompanied by initial eonditions to fully determine T(qj,t). 

Here, consider that the initial time is tg and the potential is V eht, where the positive... 

Virtually any cooling water component contacting low-pH water may be corroded. However, there are appreciable differences as to corrosion severity and initiation times depending on alloy composition, kind of acid, and location. 

The state of a system may be defined as The set of variables (called the state variables) which at some initial time Iq, together with the input variables completely determine the behaviour of the system for time t > to -... 

Let us envisionhow thiscanworkwith simple examples first, one taken at initial time... 

Fig. 14 shows mobility profiles aeross two pores with a filling of 74 and 96 pereent. The figure displays the mean-square displaeement after 10 ps as a funetion of the p eoordinate of the water moleeule at initial time. The mobility is highest in the eenter of the pore and lowest near the pore surfaee. When the pore is almost eompletely filled (full line), the mobihty is more or less eonstant in the range 0 < / < 10 A and then deereases monotonieally. 

Here, m(tp) is the mass of the system contents at final time t and m(t ) is the mass at initial time t . As before, both component and overall mass balances may be written in integral form. 

Procedure. Concentration of n-BuLi in the feed was measured by titration (15). The reactor was filled completely with styrene monomer solution in toluene initially. Time was measured from the moment initiator and monomer feed was initiated. The reaction was... 

This procedure would generate the density amplitudes for each n, and the density operator would follow as a sum over all the states initially populated. This does not however assure that the terms in the density operator will be orthonormal, which can complicate the calculation of expectation values. Orthonormality can be imposed during calculations by working with a basis set of N states collected in the Nxl row matrix (f) which includes states evolved from the initially populated states and other states chosen to describe the amplitudes over time, all forming an orthonormal set. Then in a matrix notation, (f) = (f)T (t), where the coefficients T form IxN column matrices, with ones or zeros as their elements at the initial time. They are chosen so that the square NxN matrix T(f) = [T (f)] is unitary, to satisfy orthonormality over time. Replacing the trial functions in the TDVP one obtains coupled differential equations in time for the coefficient matrices. 

A model developed by Leksawasdi et al. [11,12] for the enzymatic production of PAC (P) from benzaldehyde (B) and pyruvate (A) in an aqueous phase system is based on equations given in Figure 2. The model also includes the production of by-products acetaldehyde (Q) and acetoin (R). The rate of deactivation of PDC (E) was shown to exhibit a first order dependency on benzaldehyde concentration and exposure time as well as an initial time lag [8]. Following detailed kinetic studies, the model including the equation for enzyme deactivation was shown to provide acceptable fitting of the kinetic data for the ranges 50-150 mM benzaldehyde, 60-180 mM pyruvate and 1.1-3.4 U mf PDC carboligase activity [10]. 

The temperature rise 8 at the initial time t for a three-layer system can be given by... 

In order to solve the differential equations, it is first necessary to initialise the integration routine. In the case of initial value problems, this is done by specifying the conditions of all the dependent variables, y, at initial time t = 0. If, however, only some of the initial values can be specified and other constant values apply at further values of the independent variable, the problem then becomes one of a split-boundary type. Split-boundary problems are inherently more difficult than the initial value problems, and although most of the examples in the book are of the initial value type, some split-boundary problems also occur. 

It is noted that the initial time (t0) where the computation of all integrals begun, does not affect the determination of the slope at any later time segment. It affects only the estimation of the constant in the linear model. 

This research has given insight to a very unique bicontinuous blend system. It has also shown that the pore structure and release rates from EVAc matrices are not only dependent on particle size and loading but also on the blending technique. It becomes apparent that it is possible to tailor these systems not only for release rates but also for initial time of release of insoluble biologically active agents. 

Returning to the problem illustrated in Fig. 1, the question is How is the pendulum put into motion at an initial time fo ... 

The following sections of this chapter demonstrate the applicability of the above-mentioned adaptations to completely batch operations using an hypothetical example of completely batch processes drawn from experience at an agrochemical facility. Initially, time is treated as the primary constraints and concentration as... 

Elution in the second dimension need not be executed until solute is present in the first sample loop. This predelay period allows the first-dimension column void solvent to be dumped to waste collection prior to the arrival of the first retained component. After some initial time, the regular sampling interval 7j = 7) = 7 3 is started. 

There were substantial problems with impurities and degassing in the initial time-resolved IR measurements on Cr(CO)6 in solution. The spectroscopic results were very encouraging, but an unidentified Cr(CO)sX species (X = impurity) was observed (60). The system has now been examined in detail by the Miilheim group (96), who overcame the earlier experimental problems. 

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